Therapeutic molecules such as antibodies are valuable tools in today's treatment of various disorders, including treatment of cancers and immune disorders. The process of screening immune cells to identify potential therapeutic antibody candidates generally begins with the identification and isolation of antibodies and/or antibody-secreting cells (ASC) producing antibodies that bind specifically and with high affinity to a desired antigen. The process can include generation and random evaluation of very large phage display libraries, isolation of antibody secreting cells from human samples or transgenic mice, and/or high throughput screening of antibody binding to a selected target. This screening is only a first step in a laborious process that seeks to identify those antibody secreting cells producing antibodies with high binding affinity and specificity to a target antigen, but also able to trigger the cellular responses necessary for the diagnosis and treatment of disease. Rapid and efficient analytical systems and methods for screening both binding and functional activities are needed to advance the pace of drug discovery and development.
The in vitro evaluation of antibody function is based on complex interactions among antibodies, immune cells, and target cells, and generally requires large amounts of antibody from each candidate antibody-secreting cell. To obtain sufficient material, the candidate cells may be immortalized and expanded. This not only delays functional screening by several months, it also causes expensive and time consuming analyses of many potential antibodies and/or antibody-secreting cells that will not ultimately be of therapeutic value.
There is a need for methods and systems for screening of particles, for example immune cells such as antibody secreting cells, in a rapid and efficient manner that leads to early identification of candidate therapeutic molecules having useful functional properties for therapeutic product development.